Pulmonary surfactant ( PS ) compromises lipids and surfactant proteins (SP) and lines on the alveolar air-liquid interface. It can reduce surface tension, prevent alveoli from collapse and reduce alveoli edema by disaturated dipalmitoylphosphatidylcholine. It also modulates the pulmonary immunology by SP-A and SP-D. In this study,we established a rat model of immunocompromised host (ICH) with pulmonary infection of Pseudomonas aeruginosa (P. aeruginosa), then studied its pulmonary inflammatory reaction and analyzed the concentration of lipids and SP-A in bronchoalveolar lavage fluid (BALF) during infection.
Animals ; Bronchoalveolar Lavage Fluid ; chemistry ; microbiology ; Lipids ; analysis ; Lung ; microbiology ; Male ; Neutrophils ; physiology ; Pneumonia, Bacterial ; immunology ; metabolism ; Proteolipids ; analysis ; Pseudomonas Infections ; immunology ; metabolism ; Pulmonary Surfactant-Associated Protein A ; Pulmonary Surfactant-Associated Proteins ; Pulmonary Surfactants ; analysis ; Rats ; Rats, Sprague-Dawley

Apoproteins ; analysis ; Epithelium ; chemistry ; ultrastructure ; Humans ; Lung ; chemistry ; pathology ; Nuclear Proteins ; analysis ; Pulmonary Sclerosing Hemangioma ; chemistry ; pathology ; Pulmonary Surfactant-Associated Proteins ; analysis ; Secretory Component ; analysis ; Thyroid Nuclear Factor 1 ; Transcription Factors ; analysis

ATP-Binding Cassette Transporters ; genetics ; DNA Mutational Analysis ; Humans ; Infant ; Lung ; pathology ; physiopathology ; Lung Diseases, Interstitial ; diagnosis ; genetics ; pathology ; Mutation ; genetics ; Pulmonary Alveoli ; pathology ; Pulmonary Surfactant-Associated Proteins ; deficiency ; genetics

BACKGROUND: Pulmonary damage resulting from lipid peroxidation is a principal effect of paraquat intoxication. The host-defense functions of surfactant are known to be mediated by the surfactant proteins A and D (SP-A and SP-D, respectively). The primary objective of this study was to evaluate the variations over time in levels of surfactant protein and lipid peroxidation (LPO) in lung tissue following free-radical-induced injury. METHODS: 42 adult, male, Sprague-Dawley rats were administered intraperitoneal injections of paraquat (35 mg/kg body weight). SP-A and SP-D levels were determined via Western blot. LPO in the left lung homogenate was measured via analyses of the levels of thiobarbituric acid-reactive substances. RESULTS: LPO levels peaked at 6 hours, with no associated histological changes. SP-D levels increased until hour 12 and declined until hour 48; SP-D levels subsequently began to increase again, peaking at hour 72. SP-A levels peaked at hour 6, declining thereafter. CONCLUSIONS: We suggest that in the early phase of paraquat injury, SP-D levels reflect alveolar damage and that de novo synthesis of SP-D takes 72 hours. Levels of SP-A, on the other hand, reflect abnormalities in the surfactant system in the late stage of paraquat intoxication. Surfactant proteins may play a role in protecting the lungs from reactive oxygen injury. A time-dependent variation has been observed in the levels of surfactant proteins A and D following paraquat injury, and it has been suggested that these proteins play a role in the protection of lung tissue against ROS-induced injuries.
Animals ; Free Radicals/*toxicity ; Herbicides/*toxicity ; *Lipid Peroxidation ; Lung/*drug effects ; Male ; Paraquat/*toxicity ; Pulmonary Surfactant-Associated Proteins/*analysis ; Rats ; Rats, Sprague-Dawley ; Reactive Oxygen Species/toxicity ; Respiratory Distress Syndrome, Adult/*chemically induced

OBJECTIVEAlveolar epithelium impairment is one of pathological changes associated with chronic lung disease (CLD). Hoxb5 is one of the few homeobox genes strongly expressed in the developing lung. This study investigated the expression of HoxB5, SPC and AQP5 in rats with CLD in order to explore the role of Hoxb-5 in impairment and reparation of alveolar epithelium.

METHODSEighty neonatal rats were randomly exposed to hyperoxia (model group) or to room air (control group) (n=40 each). The CLD model was induced by hyperoxia exposure. The expression of HoxB5, SPC and AQP5 protein and mRNA in the lung tissue was detected by immunohistochemistry and RT-PCR 1, 3, 7, 14 and 21 days after exposure.

RESULTSIn the model group HoxB5 expression significantly decreased 7, 14 and 21 days after hyperoxia exposure. SPC expression decreased 3 days after hyperoxia exposure but increased significantly 7, 14 and 21 days after hyperoxia exposure as compared to the control group. AQP5 expression was progressively reduced with prolonged hyperoxia exposure.

CONCLUSIONSHyperoxia exposure may lead to alveolar epithelial cell (AEC) damage in neonatal rats. The increased SPC expression and decreased AQP5 expression suggested that the ability of differentiation and transformation of AECII into AECI decreased in neonatal rats with CLD. The decreased HoxB5 expression following hyperoxia exposure might contribute to a decreased ability of differentiation of AECII.

Animals ; Animals, Newborn ; Aquaporin 5 ; analysis ; genetics ; Chronic Disease ; Female ; Homeodomain Proteins ; analysis ; genetics ; Hyperoxia ; complications ; Immunohistochemistry ; Lung ; pathology ; Lung Diseases ; etiology ; metabolism ; Male ; Pulmonary Surfactant-Associated Protein C ; analysis ; genetics ; RNA, Messenger ; analysis ; Rats ; Rats, Wistar ; Reverse Transcriptase Polymerase Chain Reaction

ATP-Binding Cassette Transporters ; genetics ; metabolism ; Animals ; Biological Transport ; Child ; DNA Mutational Analysis ; Humans ; Hypertension, Pulmonary ; genetics ; metabolism ; Lung Diseases, Interstitial ; genetics ; metabolism ; Molecular Sequence Data ; Mutation ; Polymerase Chain Reaction ; Protein Conformation ; Pulmonary Surfactant-Associated Proteins ; genetics ; metabolism ; Respiratory Distress Syndrome, Newborn ; genetics ; metabolism